1. Field of the Invention
The invention relates to control circuits, and more particularly to circuits controlling rotation of motors in motor systems.
2. Description of the Related Art
FIG. 1 is a schematic diagram of a conventional printer motor system. In FIG. 1, printer motor system 10 usually comprises a control circuit 12, a pre-driver circuit 14, an H-bridge circuit 16 and a motor 18. Control circuit 12 generates a plurality of control signals 13 to pre-driver circuit 14. Pre-driver circuit 14 generates a plurality of driving signals 15 to H-bridge circuit 16 according to the control signals 13. H-bridge circuit 16 generates control signals 17 corresponding to driving signals 15 to control the rotation of motor 18.
However, the print quality of printer motor system 10 is influenced by the accuracy of the rotation speed and the initial position of motor 18. For example, printing position is shifted when the initial position of motor 18 is in error, affecting quality of the printed document. Thus, printing quality of printer motor system 10 is increased when the rotation speed and the initial position of motor 18 is controlled accurately, making accurate generation of control signals 13 using control circuit 12 a priority.